We strive to create patterns that are as accurate as possible. However from time to time mistakes still happen and errors occasionally slip through.
If a pattern as been updated we will get the electronic version to you as soon as possible by email. If you've also stored it in your ravelry library you can check if there as any updates are available directly in your library there.
All know errata will be listed directly on ravelry pattern page also.
If you need help with a pattern there are a few different ways of finding support.